Understanding land use influence to coastal

ecosystems in the Rio Grande de Manati Watershed

MÓNICA A. FLORES HERNÁNDEZ & ROSA SÁEZ URIBE

University of Puerto Rico, Río Piedras Campus

Department of Environmental Sciences http://www.fideicomiso.org/slideshow-esp.html

Research Problem The economic shift and the population growth have provoke significant

changes in watersheds that have altered its water and sediment dynamics (Crk, Uriarte, Corsi, & Flynn, 2009; Hosonuma et al., 2012; Macedo et

al., 2012).

Sediment discharge being one of the modified parameters.

An increase in sediment inputs could result in degradation of coastal

ecosystem (Fabricius, 2005).

Decreasing sunlight and oxygen availability.

Total burial of an ecosystem.

Understanding sediment dynamics in a

watershed is important to attend the

problem at its source and to implement

more integrated management practices.

Milliman and Farnsworth (2013)

Goals and Objectives

Main Goal:

Study sediment dynamics along the Río Grande de Manatí

watershed to infer how the land use is influencing riverine inputs to

coastal ecosystems.

Objectives:

Relate the land use in the watershed to the sediment inputs in the river .

Analyze river contribution to the coastal zone trough suspended sediment.

Establish a relationship between suspended sediment concentration,

turbidity and sunlight attenuation in the coast.

Outreach for students of public schools through workshops.

Methodology Land use:

A land use map will be constructed using remote sensing techniques

focusing primarily on sources of sediment production and transport

(bare lands, roads, urban areas) and areas of sediment catchment

(forest, pastures).

Remote sensing and Soil & Water Assessment Tool (SWAT) modeling

will be used.

This model will be calibrated with different values of topography,

rainfall, temperature, land use, soil type and other parameters

belonging to the climate and topographic conditions of the Río

Grande de Manatí watershed.

Methodology

Sediment sampling:

Suspended sediment samples will be obtained in three (3)

sites along the Río Grande de Manatí River:

Samples will be tested for turbidity, filtered, dried and

weighted in the lab to determine total suspended solids

(TSS).

Turbidimeters will be left in each site to collect data

continuously for the period of study.

Data will be downloaded biweekly.

USGS 50038100 USGS 50035000

Outfall influence to the coast:

Reflectance and radiance measurements of the outfall

influence throughout the period of study will be obtained using

satellites images from NOAA AVHRR and Orbview-2 Sea WiFS.

In situ measurements coincident with clear-sky satellite overpasses

will be made 6 times during the sample period to correlate with

satellite information.

This data will be incorporated to SWAT.

Methodology

Activities and Timetable 2016 J F M A M J J A S O N D

Suspended sediment

sampling (river)

X

X

X

X

X

X

X

X

X

X

Suspended sediment

sampling (coast)

X

X

X

Sediment sample processing

X

X

X

X

X

X

X

X

X

X

Data analysis

X

X

X

SWAT Training

X

X

Land use map generation

with SWAT

X

X

X

X

Annual report

X

2017 J F M A M J J A S O N D

Suspended sediment

sampling (river)

X

X

X

X

X

X

X

X

X

X

Suspended sediment

sampling (coast)

X

X

X

Sediment sample

processing

X

X

X

X

X

X

X

X

X

X

Data analysis

X

X

X

Workshop preparation

X

X

Workshops at public

schools

X

X

Final report X

Potential Benefits

With this research, we will be able to understand sediment generation and transport along the watershed.

Our findings could translate in recommendations for better and

more integrated management practices and strategies to control sediment inputs to the coastal zone.

With a better understanding and a better management of the

sediment inputs along the watershed, both coastal and riverine ecosystems could be properly tended.

Budget Summary

COST ITEM UPR fund pairing

Personnel $6,000

$18,000

Co-PI’s summer stipend

Stipend for two (3) undergraduate

students .

$39,400 in Co-PI’s salary for 2 years

$12,000 in stipend for 2

undergraduate students for 2 years

Travel $300 Workshops in schools 0

Equipment $12,000

$1,100

$2,400

Two turbidimeters (Eureka Water

Probes)

Portables Turbidimeters (Hatch

2100)

Boat rental (6 trips)

$6,000 1 turbidimeter

$4,903 1 Portable flowmeter

Expendable

Supplies and

Equipment

$1,500

$1,690

Transportation to sample sites (46

trips)

Water quality equipment and

educational material for workshops

Indirect costs 48% of Direct Costs, current UPR

rate.